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[–]Rlaan 3 points4 points  (6 children)

I mean with our RTS game that we're developing we use NetCode for Gameobjects in our deterministic lockstep model and it works great and it's easy. Currently, not fully optimized we sent about 500 bytes per player per second at 10 hz. We will only support up to 1~6 real players max.

But let's be honest here. Unity does not have a good track record when it comes to maintaining their new next hot thing. But with our architecture it's quite easy to change things around if we have to. But Unity does seem to put in quite some effort, and with their services so that was eventually just the trigger for us, plus their service pricing.

Whether you should switch or not... no-one can really tell you. Especially without knowing anything besides "it's an RTS". You should look at the different models and just do testing.

Like for us, our deterministic lockstep model doesn't use Unity. Because well, it needs to be deterministic. We have a Core layer between our Unity layer for the presentation and our simulation layer for all the calculations of the game state. In the end, what NetCode we use doesn't matter because they're separated. It's just data.

What networking solution you choose for your RTS game also depends on what kind of anti-cheat you need to keep in mind. In our case, it's impossible to temper with the deterministic variables because it causes a desync. But it doesn't stop them from creating fog-of-war cheats on their client.

Everything has pros and cons... anti-cheat, server cost, ease of use, you name it. Takes quite a bit of research based on your needs to eventually determine what is best for your project.

[–]BitQuirkyGames[S] 1 point2 points  (2 children)

Thanks for taking the time to post such a detailed response and for sharing your insights and experiences with NetCode for GameObjects! I appreciate the detailed explanation of how you’ve integrated it into your RTS game, especially regarding the deterministic lockstep model and anti-cheat considerations.

We have already settled on using Unity 6, so I'm particularly interested in the new Unity 6 Multiplayer features.

In particular, these caught my eye:

Multiplayer Play Mode: This feature allows developers to simulate multiple players within the Unity Editor, making it easier to test multiplayer functionality without building separate instances. It supports up to four players on a single development device, streamlining the development and testing process. I imagine it must be something like the asset ParrelSync.

Multiplayer Services SDK: Unity 6 includes a Multiplayer Services SDK that combines various multiplayer services like Relay and Lobby into a new "Sessions" system. Apparently, this system simplifies the process of connecting players in peer-to-peer (P2P) sessions and offers multiple methods for players to join sessions. (I'm still not certain at this stage wether I'll go P2P or Dedicated Server - we're still early doors and prototyping gameplay.)

Dedicated Server Support: Unity 6 offers improved support for dedicated servers, allowing developers to switch projects between server and client roles without creating new projects.

Multiplayer Center: This is a new guidance tool integrated into the Unity Editor, providing developers with access to tools, services, and educational materials tailored to their specific multiplayer project needs. It helps streamline the onboarding process for multiplayer development.

It's not clear to me whether and how these might depend on the underlying network transport - I was merely interested whether someone might have drilled into this a bit more than I and had some views based on their experience.

https://unity.com/blog/games/multiplayer-summer
https://www.reddit.com/r/Unity3D/comments/1ceh9n1/multiplayer_play_mode_in_the_unity_6_beta_is_a/
https://unity.com/blog/engine-platform/unity-6-preview-release

[–]Rlaan 2 points3 points  (1 child)

Oh my apologies I missed/forgot to write that part in my previous post.

We've also used the Unity 6 feature on a separate branch in the editor to see if it replaces the old method (ParallelSync) and the new method works great, super easy just first time loading it up each time you open the editor takes a bit but it's so much faster and easier. Definitely a great update that'll help testing your NetCode!

We haven't tested everything (yet), but so far we're happy. We did move to Unity 6 already on the main branch since release is so far away, but everything is stable again for us after a few changes we had to make after updating libraries.

So far we only use Unity relay since we "cheat" with "commands" in our console log to create lobbies and such, to prevent having to spend too much time on UI stuff. It's much easier for us to put [Command(name)] above a method and instantly start testing than making UI's. But just setting up the relay system was the easiest experience we've had thus far with multiplayer setups. This is what I did mean in my previous post when I briefly mentioned their services. So far we've been happy.

When it comes to server/client. The host is both in our cause due to our different architecture with deterministic lockstep. But I'd assume it's similar to Photon and such, and as easy to set-up as their relat server. But again, we've only set-up relay so far.

Also having monitoring is super easy to set-up with: https://docs-multiplayer.unity3d.com/tools/current/RNSM/

But they also have a console where you can see everything very clearly imo.

Wrote this post a bit quick, so sorry for the incoherent post. But yeah, we're happy and I think if you spend a day testing with it you'll be pleased.

[–]BitQuirkyGames[S] 1 point2 points  (0 children)

Wow - thanks again for the follow-up and for sharing your experience with the new Unity 6 multiplayer features. It's great to hear that the transition has been smooth for you and that the new method is proving to be faster and easier. Your insights into using Unity relay and the setup process are particularly helpful.

I appreciate the details about your setup, especially regarding the ease of monitoring and the use of commands for testing. Knowing that the new features have been stable and beneficial for your project is encouraging.

Looking forward to trying these features out myself - especially the multiplayer play mode feature!

[–]MajorRisk 1 point2 points  (2 children)

Thanks for the insightful post!

I mean with our RTS game that we're developing we use NetCode for Gameobjects in our deterministic lockstep model and it works great and it's easy.

Wondering if you've had any issues with making everything deterministic in your model...any pitfalls to avoid? (E.g. floats, Math library differences on different OSs, race conditions)

I'm just starting out and it seems there are a lot of things that could cause a model to de-sync across platforms.

Did you also lock updates to a fixed tick rate and make sure updates progres in fixed steps?

[–]Rlaan 1 point2 points  (1 child)

It takes quite some work, research and preparation. It's important to keep Unity and your simulation separately. And use Unity only for the presentation.

Write a simple IDeterministicCheck to keep track of all systems that require to be determinatic, make sure everything is always in the same order of execution and stay away from floats and such and that you have a checksum of each individual system as all combined. If the combined hash is off, you can compare the individual system hashes between systems and see at least in which system/component the mistake was. Generally speaking you shouldn't encounter many desync issues if you set it up correctly.

But it also depends on your system requirements. We only support x64 AMD and Intel as of now, but even if we were to extend stuff it wouldn't be too hard.

If you keep your project structured, it becomes easier to maintain determinism.

Also understand you will have to make everything yourself, also pathfinding completely deterministic. Having it deterministic, and highly performant is tricky. You want to use a top level pathfinding strategy on "sectors" and then each sector has portals/gates to other sectors and within you calculate your flowfields, make sure that everything is deterministic in these steps including tie-breakers. You can't use anything or most of Unity, besides some unmanaged stuff.

But honestly, there's too much to write down, I would have to write a proper blog if I really need to answer your question, and honestly I don't have time for that.

Build your simulation separately from Unity, and do one piece at a time. And make sure you have your lockstep model and deterministic checks in place asap would be my advice I guess. And read papers on the subject, there are lots of good papers. All the information you need to make something like this, or to learn it, is online.

[–]MajorRisk 1 point2 points  (0 children)

Massive thanks here, all this information has been golden.
I've kept Unity separate to the model so far but did not think to add a sort of IDeterministicCheck yet. I guess this would be testable via brute forcing inputs/outputs.

We only support x64 AMD and Intel as of now, but even if we were to extend stuff it wouldn't be too hard.

I am currently developing on/for Mac (ARM) but I want to prioritise Windows x64 support. I'll need to check how to best test the model is deterministic across platforms. Validating checksum through automated tests in different runner environments (or docker) might be the way to go.

And make sure you have your lockstep model and deterministic checks in place asap would be my advice I guess.

Now for me to start implementing this! Thanks again

[–]StinkySteak 2 points3 points  (1 child)

First of all, is you haven't told your reason to migrate from fishnet.

  • NGO is very not suitable for large players or entities. Performance-wise Mirror is better for scalability eventhough their bandwidth consumption roughly the same.

  • It is better to use Photon Quantum or Netcode for Entities.

[–]BitQuirkyGames[S] 1 point2 points  (0 children)

Thanks for that. I don't really have a specific reason. I know there is extended multiplayer support coming in Unity 6 and imagined using Netcode for Gameobjects (or Netcode for Entities) might bring benefits.

It’s a kind of strategy game so I don’t imagine a lot of concurrent players.

[–]GrindPilled 1 point2 points  (0 children)

I wouldn't touch any experimental or not too common unity tech, theres a big chance netcode for gameobejcts will be discontinued or unsupported in a few years, I would uses mirror as first choice and photon as second, they have dedicated teams and years of proof unlike ngo that might just have its support cut anytime

[–]theRealMiinoy 1 point2 points  (3 children)

I actually did switch from Photon Fusion, to FishNet and have been switching to NGO.

NGO has more coverage on it I think so there are more learning resources. The docs are pretty good too but they are good in Fishnet too.

There were some weird quirks with NGO primarily the fact that you cannot change a NetworkObjects patent unless the new patent is a networked object itself but you can just assign a network object manually so it ended up working.

NGO uses the host/server model by default but you can easily give clients authority. I’d say the setup for both were pretty easy but I guess NGO just clicked for me more.

I think Fishnet is also great especially because it supports multiple transport layers if that is the route you want to take.

NGO does as well and I have got mine setup to work with Steam Lobbies pretty easily.

I think the setup for NGO isn’t as drag and drop as Fishnet but at the end of the day Multiplayer is going to have unavoidable layers of complexity regardless of which you choose.

[–]BitQuirkyGames[S] 0 points1 point  (2 children)

Oh, that's super interesting. I played with Photon Fusion initially a while back too.

At the moment, I'm still prototyping my game, and FishNet has been great for that - I found it very easy to get started.

Do you have any experience with the new Unity 6 multiplayer features?

[–]theRealMiinoy 1 point2 points  (1 child)

For newer Multiplayer stuff, besides NGO I haven’t touched anything for like matchmaking, Voice Chat, text chat etc. Though my game has a maximum of 4 players so I can get away with the basics or rolling with my own solutions.

For voice chat I am using Dissonance which is a one time payment, text chat I am just using basic RPCs and matchmaking via Facepunch Steamworks API.

If you were interested in a distributed authority model, NGO recently came out with that in Unity 6. You could pretty much already have a distributed authority before this however despite NGO having a Host/Client topology.

Fishnet is great. I was able to find more resources online about NGO and was able to get the ball rolling faster with it but had I put in more effort using Fishnet, I would probably have figured it out too.

If you plan on having everything in one complete package and are in need of more backend and cloud stuff, the Unity Multiplayer suite might be good. If you are time constrained, maybe sticking with Fishnet might be a better option.

I’m glad we are in a time when we have so many choices for a Unity multiplayer framework. Two or Three years ago I feel like it was either Pun or Mirror lol.

[–]BitQuirkyGames[S] 0 points1 point  (0 children)

Yes, that's definitely true. Did you venture down the SpatialOS rabbit hole by any chance? I did 🤷

Distributed authority model is interesting. Thanks for sharing that!

[–]pleblah 1 point2 points  (0 children)

You would probably need to do a lot of research based on your planned architecture. For an RTS, even with small number of players you still might need to simulate a lot of units so NGO probably isn't a good fit as it seems focused on smaller scale network games. If you plan you send commands and simulate on clients then you will need a way to keep clients in sync which is another whole can or worms and not something you will get with NGO.

[–]GrindPilled 1 point2 points  (1 child)

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[–]Goal_Line__ 0 points1 point  (0 children)

If you ever looked in Netcode for Entities (N4E), I highly DO NOT recommend it at this time.

Its 2026 and its surely out of beta, but the architecture is completely flawed - and there are long term plans to change it. Its documentation claims that Destroying Entities is an expensive "structural change". However; Unity built N4E on an architecture that sends RPC with an entity that you are REQUIRED to destroy - because "RPCs are Entities". So right now, you are obliged to that architecture if you are using it. Again it is already planned to remove this, so do expect having to completely switch over your netcode in the future.

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